Machine for centrifugal formation of plastic bodies



H. BARKSCHAT. I

MACHINE FOR CENTRIFUGAL FORMATION OF PLASTIC BODIES.

APPLICATION FILED MAR. I, 1920.

Patented Sept. 20,1921.

I HENRY BARKSCHAT, OF'LOS ANGELES, CALIFORNIA.

MACHINE FOB CENTRIFUGAL FORMATION OF PLASTIC BODIES.

Specification of Letters Patent. Patented Sept. 20, 1921.

Application filed March 1, 1920. Serial No. 362,528.

To all whom it may concern:

Be it known that I, HENRY BARKSCHAT, a citizen of the United States, residing .at Los An eles, in the county of Los Angeles, State of galifornia, have invented new and useful Improvements in Machines for Centrifugal Formation of Plastic Bodies, of which the following is a specification.

This invention relates to improvements in machines for the centrifugal formation of plastic bodies and particularly concrete bodies. An object of the invention is to provide simple and effective improvements in such machines which will add to their efiiciency and durability.

In machines of this general character there have been very objectionable difficulties experienced. It has been found practically impossible to construct perfectly balanced molds and machines and it has been found difiicult to exactly center the molds in the machines. When long molds are being used it is necessary to use several supporting units or machines and there is a tendency for the molds to spring or bend between the machines, or points of support. For the proper formation of bodies from plastic materlal, such as concrete, in a mold, it is necessary to rotate the mold from 300 to 1,000 revolutions per minute according to the size of the concrete body, the constituents of the material, the density or compactness desired in the finished article, etc. The high rotative speeds and the above mentioned structural difiiculties cause violent jarring or vibration of the mold and the machines. Although the various parts of the machines are made heavy and strong the vibration causes failure of various parts after the machines have been in operation only a short time. It will be readily understood that the failure of a part when the machine is in operation is very apt to, and in fact often does, cause great damage not on] to the remainder of the machine but a so to the mold. The repeated failure or breaking down of the machine bearings and axles has not only made necessary expensive repairs but has also caused a great loss of time and has been a great in convemence.

By the present invention improvements are made in this class of machinery which overcome these difficulties and make the machines efiicient and durable. The invention provides resilient meansin the machines for taking up or relieving the strains due to vibration, in such a manner as to prevent straining or overloading of any part or parts of the machine. Further objects of the invention as well as the details of construction of a specific preferred form will be readily understood from the following detailed description throughout which reference is had to the accompanying drawings, in which Figure 1 is a side elevation showing two units on machines carrying a single mold; Fig. 2 is an end elevation of a machine showing the arrangement of the supporting wheels; Fig. 3 is an enlarged detailed view showing a portion of the machine; and Fig. 4 is a section taken as indicated by line 4-4: on Fig. 3.

Throughout the drawings numeral 10 designates the cylindrical carriers or drums in which the mold is carried. In Fig. 1 of the drawings, is shown a comparatively long mold 11 which requires two carrier machines. Due to the variation in the lengths of the molds several machines are usually mounted in line on a base 33. When a long mold is to be rotated as many machines as are necessary to hold it may be used and When a small mold is to be rotated. one machine may be used. When, as is usual, two or more machines are used to support a single mold it is very difiicult to accurately center the machines and to center the mold in the machines; in fact, it is practically impossible to do so, or impracticable to attempt to do so in actual manufacturing operations. The result of inaccurate alinement is vibration and jarring when the machines are retated at a high speed.

The mold 11 is the type of mold commonly used in connection with machines of this character. Molds although carefully and accurately made are practically never perfectly balanced. The result is that when a mold is rotated rapidly there is caused vibration and jarring even if it is perfectly centered in the machine or machines. This vibration and jarring combined with that due to lack of allnement explained in the receding paragraph causes the mold to vi rate, and the mass of the parts and the speed of rotation causes the vibration, although usually short, to be of great force. I

As has been hereinbefore described one or more machines ma .be used at a time depending upon the s1ze of the mold. The machines are all constructed in the same manner so I will proceed to describe only a single machine.

At the middle of the drum 10 there is a crowned portion 12 over which a belt 13 may run. The belt may be driven by a pulley 14. When two or more machines are used to support a single mold it has been found that it 1s necessary to drive only one machine.

At each end of the drum 10 there is an enlarged portion 15 in which are carried chuck jaws 16. The chuck jaws are arranged so as to engage the mold 11 and hold it firmly and approximatelyconcentrically in the drum 10. The chuck jaws are arranged so that they may be withdrawn from the mold suflicientl to allow it to be easily removed from or p aced in the drum.

Due to the weight of the mold and the high rotative speeds it is necessar that the drum should be well supported. he drum is supported by three pairs of rollers 18 which engage roll ways 17. There is a" roll way 17 on each side of the crowned portion 12. The rollers 18 are mounted in pairs on shafts 19 so that each one engages one of the roll ways. The rollers 18 are approximately equally spaced around the drum 10 as shown in the drawings. Being thus arranged the two lower pairs of rollers act as supports for the drum while the top pair holds the drum down in position.

The ends of shaft 19 are carried in bearing blocks 20 which are mounted in frames 22. The frames are triangular shaped skeleton castings on the bottom of which are flanges 22 by which they are rigidly mounted on base 33. Extending between the frames 22 are tie rods 30 which brace the frames and firmly connect them. The frames are preferably spaced far enough apart so that the drum 10 can be lifted out or placed in the machine when the upper shaft 19 is removed. The bearing blocks 20 are carried in guide ways or slots 21 in the frames. The slots 21 which carry the bearing blocks in which the lower shafts 19 are carried are horizontal while the slots in which the upper shaft 19 is carried are vertical. The bearing blocks 20 are slidable in the slots 21 and are prevented from moving out of the slots and kept in alinement by flanges 23 0n one side of each block and a late 24 on the other side.

here are set screws 25 screw threadedly engagfd in the frames 22 so that they extend 1nto t e slots 21. Between the ends of the set screws and the bearing blocks there are springs '26. The springs 26 are preferably heavy leaf sprin s about of an inch to i of an inch thick. e springs are so shaped'that the ends 29 engage the bearing blocks while the middle portions 28 are raised and engage the set screws 25. With the particular arrangement provided by the invention springs of equal strength can be arranged at each of the several blocks even though the blocks carrying the lower shaft are subject to considerable more pressure than the blocks carrying the upper shaft. The slots which carry the blocks of the lower shaft being horizontally disposed, or substantially horizontally disposed, prevent all of the load supported bythese blocks being transmitted to the springs. In any particular case the slots for the blocks of the lower shafts can be disposed at an angle relative to a line extending radially through the axis of the machine which will cause the springs back of these blocks to receive substantia} y the same pressure as the springs back o the Hooks supporting the upper shaft. This construction is particularly important as it causes the mold to be equally yieldingly supported inall directions. Ifv it were not for this arrangement and if all of the blocks were movable in directions substantiall radial to the axis of the machine, or in irections all the same .relative to the mold the springs of the blocks of the lower shaft would be somewhat compressed by the weight of the mold and would not thereafter yield as readilyv as the springs at the blocks of the upper shaft. The drum 10 is centered in the machine by adjusting set screws 25.. When the machine is properly adjusted all the rollers 18 are in engagement with the drum 10, and the set screws 25 are then locked by lock nuts 27.

When the machine is in' operation the vibration of the mold is ractically all taken up by the springs 26. lthough all the vibration is not sto ped by the springs the force of the vibration is broken. The force of the vibration acts directly upon the rollers 18 and therefore comes upon the shafts 19 and bearings 20. The springs 26 being between the bearing blocks and the set screws provide a resilient mounting for the shafts and prevent the vibration from causing failure of said shafts and bearings. Although a spring 26 has been shown .in connection with each bearingv block 20 ithas been found that it is only necessary in practice to use springs in connection with.

the upper bearing-blocks. V The exact details hereinabove set forth may be varied without departing from the invention therefore I do not wish to limit myself to the details set forth but wish to reserve tom self any changes or modifications that may all within the scope of the followin claims.

aving described a preferred form of my around the mold to equally yieldingly support the mold.

2. In a machine of the character described, a frame, a mold, and means for rotatably supporting the mold in the frame comprising a plurality of rollers supported by the frame at spaced points around the mold to equally yieldingly support the mold.

3. In a machine of the character described, a frame, a mold, and means for rotatably supporting "the mold in the frame comprising a plurality of rollers equally yieldingly mounted in the frame at various points aroundthe mold being movable in directions to cause the mold to be yieldingly supported equally in all directions.

4.,In a machine of the character described,-

a frame, a mold,and means for rotatably supporting the mold in the frame comprising a plurality of rollers equally yieldingly mounted in the frame at varlous points around the mold those at the upper portion of the mold being movable substantially radially relative to the axis of the mold and those at the lower portion of the mold being movable in directions angular relative to lines extending radially of the axis of the mold.

In a machine of the character described, a frame,a mold,and means for rotatably supporting the mold in the frame comprising, a plurality of rollers movably carried by the frame at spaced points around the mold, and

like springs in connection with the rollers to cause them to yieldingly support the mold the rollers at the upper ortion of the mold being movable in the rame substantially radially of the mold and those at the lower portion of the mold being movable in direc tions between the horizontal and lines extending radially through the axis of the;

mold.

a frame having a plurality of guide ways,

a mold, bearing blocks slidably carried in portion of the mold being radially disposedrelative to the axis of the mold, and the guide ways in connection with the rollers at the lower portion of the mold being substantially horizontally disposed.

In witness that I claim the foregoing I have hereunto subscribed my name this 20th (lay of February 1920.

HENRY BARKSCHAT. Witness:

VIRGINIA I. BERINGER.

6. In a machine of the character described, 

